security: address assessment findings and bump to v2026.3.11

- C1: Disable Swagger UI in production (env gate)
- M1+M2: Add Helmet.js for security headers (CSP, X-Frame-Options,
  X-Content-Type-Options, Referrer-Policy) and remove X-Powered-By
- H2: Add @nestjs/throttler rate limiting (5 req/min on login/register)
- M4: Remove orgSchema from JWT payload and client-side storage;
  tenant middleware now resolves schema from orgId via cached DB lookup
- L1: Fix Chatwoot user identification (read from auth store on ready)
- Remove schemaName from frontend Organization type and UI displays

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/modules/auth/auth.controller.ts

@@ -9,6 +9,7 @@ import {
 } from '@nestjs/common';
 import { ApiTags, ApiOperation, ApiBearerAuth } from '@nestjs/swagger';
 import { AuthGuard } from '@nestjs/passport';
+import { Throttle } from '@nestjs/throttler';
 import { AuthService } from './auth.service';
 import { RegisterDto } from './dto/register.dto';
 import { LoginDto } from './dto/login.dto';
@@ -23,12 +24,14 @@ export class AuthController {
 
   @Post('register')
   @ApiOperation({ summary: 'Register a new user' })
+  @Throttle({ default: { limit: 5, ttl: 60000 } })
   async register(@Body() dto: RegisterDto) {
     return this.authService.register(dto);
   }
 
   @Post('login')
   @ApiOperation({ summary: 'Login with email and password' })
+  @Throttle({ default: { limit: 5, ttl: 60000 } })
   @UseGuards(AuthGuard('local'))
   async login(@Request() req: any, @Body() _dto: LoginDto) {
     const ip = req.headers['x-forwarded-for'] || req.ip;

backend/src/modules/auth/auth.service.ts

@@ -118,7 +118,6 @@ export class AuthService {
       sub: user.id,
       email: user.email,
       orgId: membership.organizationId,
-      orgSchema: membership.organization.schemaName,
       role: membership.role,
     };
 
@@ -177,7 +176,6 @@ export class AuthService {
 
     if (defaultOrg) {
       payload.orgId = defaultOrg.organizationId;
-      payload.orgSchema = defaultOrg.organization?.schemaName;
       payload.role = defaultOrg.role;
     }
 
@@ -195,7 +193,6 @@ export class AuthService {
       organizations: orgs.map((uo) => ({
         id: uo.organizationId,
         name: uo.organization?.name,
-        schemaName: uo.organization?.schemaName,
         status: uo.organization?.status,
         role: uo.role,
       })),

backend/src/modules/auth/strategies/jwt.strategy.ts

@@ -18,7 +18,6 @@ export class JwtStrategy extends PassportStrategy(Strategy) {
       sub: payload.sub,
       email: payload.email,
       orgId: payload.orgId,
-      orgSchema: payload.orgSchema,
       role: payload.role,
       isSuperadmin: payload.isSuperadmin || false,
       impersonatedBy: payload.impersonatedBy || null,